German Patent No. DE 198 15 082 A1 describes a transport and storage container for liquids in which an grounding element is arranged in the species-related tapping armature attached to the drain port of the inner container, and which is constructed as a curved metal sheet or small plate, extending over a portion of the inner hole of the tapping armature and connected to the base of the container via a fixing screw and an grounding lead.
This tapping armature has the following disadvantages:
The fixing screw that is screwed through the housing wall to attach the sheet or small plate, which is made of metal, in the armature housing, which is made from plastic, does not ensure that the armature is leak-proof. In transport and storage containers for certain liquid foods, the use of metal parts is not permitted, and consequently containers equipped with this armature cannot be used for such liquid foods. Finally, there is a risk with the known liquid containers that when aggressive liquids are transported or stored, the grounding element may be damaged by the liquid to such an extent that electrical grounding is no longer assured.
Certain tapping armatures for liquid containers are known having a housing that is equipped with antistatic means, but these are too expensive to be produced for a mass market.